fix(scan): allow 20-item async batches

[cdot65]

What changed

• raise asyncScan() from 5 to 20 request objects per call
• keep scan-result and report-result query limits at 5 IDs
• add a public regression proving all 20 objects reach one fetch and 21 fails before fetch
• correct guides, architecture docs, examples index, release notes, and changeset
• bump the package and SDK version to 0.13.2

Why

The current AIRS API accepts 20 prompts in one async submission, but SDK v0.13.1 incorrectly rejected valid 6–20 item batches locally.

Validation

• 1,373 tests
• format, lint, typecheck, build
• docs coverage and Docusaurus production build
• schema preflight with zero unacknowledged drift
• npm package dry-run for @cdot65/prisma-airs-sdk@0.13.2